This paper explains the mobile based controlling of various appliances. The mobile act as a transmitter for sending the signal to the micro controller which makes the appliance on or off. The DTMF technique is use for sending message pulses from mobile phone to receiver. To drive the appliances they are connected with relays. The entire circuit works with a 5v dc power supply. A decoder is placed in the receiver unit to decode the signal sent from the mobile.

Brief into the working process:

By pressing the buttons on the mobile phone two tones are generated due to DTMF technique one tone is for identifying the signal and other tone is for identifying the message signal of on or off. At the receiver unit the decoder decodes it and gives the information to the AT89C52 microcontroller. The microcontroller processes it and gives the signal to the driver which drives the relay, by which the respective relay gets on or off. The microcontroller is compiled and run on keil software. Suppose if any error occurs in sent signal then the microcontroller automatically reboots itself. As the microcontroller is a 40 pin configured device we can connect a maximum of 8 relays . if the number of appliances are more we need not change the microcontroller we can connect a multiplexer to the relays depending upon the number of devices.

Applications:

This can be effectively utilized in household purpose, for controlling the home appliance from any long distances. We can also check the status of the home appliance by using mobile. This can also be used in industrial purpose. Thus we can conclude that by using this model we can monitor the appliances in long distances.